Q. How can I research the legislative history of a law?
Because legislative histories are not prepared in the course of creating legislation, you may need to research and compile your own legislative history.
The Law Library of Congress' webpage on Federal Legislative History guide includes a list of resources to search for legislative histories and is available at: http://www.loc.gov/law/help/leghist.php
In addition to including initial steps for compiling federal legislative histories, there is also a section to search for previously compiled legislative histories under: "To learn if a compiled legislative history already exists for the law you are researching, consult these resources".
The Congressional Record is the official record of the proceedings and debates of the United States Congress. It includes a section on the "History of Bills and Resolutions."
For 1994 to present, the Congressional Record is available online at: https://www.gpo.gov/fdsys/browse/collection.action?collectionCode=CREC
For earlier Congressional Records, you may need to contact a federal depository library near you about their historical holdings of the Congressional Record. A listing of federal depository libraries is available at: https://www.fdlp.gov/about-the-fdlp/federal-depository-libraries
For further assistance with your question you may wish to contact a law library near you or the Law Library of Congress. The Law Library of Congress may be contacted at: http://www.loc.gov/rr/askalib/ask-law.html.